ACPI: EC: Add workaround for "optimized" controllers

Some controllers do not send interrupts for OBF=1 event, but send
them for IBF=0. Add workaround for them.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=8459

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>